Pipe pigs are known that are self-propelled and that are smart, in that they carry and may be controlled by electronics. However, some pipes have tight bends, for example in headers in heat exchangers, and this makes it difficult for some smart pigs to get around the bends. Conventional pigs are configured to fit centrally within pipes, either occupying the entire cross section of a pipe, or with symmetrical legs contacting the interior surface of the pipe. Although wheeled pigs are known, the symmetrical arrangement limits the wheels to a small size relative to the internal diameter of the pipe.